Cosmological Implications of the Fundamental Relations of X-ray Clusters

Based on the two-parameter family nature of X-ray clusters of galaxies obtained in a separate paper, we discuss the formation history of clusters and cosmological parameters of the universe. Utilizing the spherical collapse model of cluster formation, and assuming that the cluster X-ray core radius is proportional to the virial radius at the time of the cluster collapse, the observed relations among the density, radius, and temperature of clusters imply that cluster formation occurs in a wide range of redshift. The observed relations favor the low-density universe. Moreover, we find that the model of $n\sim -1$ is preferable.Comment: 7 pages, 4 figures. To be published in ApJ Letter

Informações tecnológicas para a exportação de coco verde livre da podridão-basal-pós-colheita.

bitstream/item/48172/1/CIT11001.pd

Mass-Temperature Relation of Galaxy Clusters: A Theoretical Study

Combining conservation of energy throughout nearly-spherical collapse of galaxy clusters with the virial theorem, we derive the mass-temperature relation for X-ray clusters of galaxies $T=CM^{2/3}$. The normalization factor $C$ and the scatter of the relation are determined from first principles with the additional assumption of initial Gaussian random field. We are also able to reproduce the recently observed break in the M-T relation at T \sim 3 \keV, based on the scatter in the underlying density field for a low density $\Lambda$CDM cosmology. Finally, by combining observational data of high redshift clusters with our theoretical formalism, we find a semi-empirical temperature-mass relation which is expected to hold at redshifts up to unity with less than 20% error.Comment: 43 pages, 13 figures, One figure is added and minor changes are made. Accepted for Publication in Ap

IMPLEMENTACIÓN EN SIMUL8 DE UN MODELO SOBRE LOS DEPARTAMENTO DE ACCIDENTES Y EMERGENCIAS

Los departamentos de accidentes y emergencias son de gran interés en el área de la simulación de eventos discretos ya que por la importancia de los servicios que prestan se hace apremiante encontrar alternativas que hagan que su rendimiento en cuanto a tiempos de atención sea lo más óptimo posibles. En este trabajo se implementa en el software Simul8 un modelo genérico desarrollado por Günal y Pidd (2006) sobre estos departamentos con el fin de comprender el funcionamiento de estos sistemas y obtener respuestas de investigación sobre la implementación de modelos genéricos y la pertinencia de la simulación de eventos discretos para este tipo de sistemas.The departments of accidents and emergencies are very interesting in simulation and discrete events areas because the importance of the services that they give became important to find alternatives to make their performance in time attention the most optimal. In this work it’s carried out in the software Simul8 a generic model developed by Günal y Pidd (2006) about these departments in order to understand the performance of these systems and to get research answers about the carrying out of generic models and the relevance of simulation of discrete events for this kind of systems

Avaliação de antibiose e não-preferência em cultivares de milho selecionados com resistência a lagarta-do-cartucho.

Dentre os fatores que contribuem para reduzir a produtividade das lavouras de milho estao as pragas, destacando-se a lagarta-do-cartucho, Spodoptera frugiperda, a qual pode reduzir a producao em ate 34%. Um dos metodos de controle de pragas, cujo custo e reduzido e nao causa efeitos indesejaveis ao ambiente, e o desenvolvimento de cultivares resistentes. Diversas fontes de resistencia foram identificadas, linhagens desenvolvidas, registradas e liberadas ao publico; entretanto, pouca informacao tem sido veiculada a respeito dos mecanismos e causas dessa resistencia. O objetivo do presente trabalho foi estudar os mecanismos de resistencia, nao-preferencia e antibiose em genotipos de milho selecionados, com resistencia a S. frugiperda. Os ensaios foram conduzidos em laboratorio e em casa de vegetacao da EMBRAPA/CNPMS. O genotipo CMS 14C apresentou antibiose influindo negativamente na biologia de S. frugiperda. 'CMS 24' e 'CMS 23' apresentaram tambem esses mecanismo, porem em menor intensidade. Foi constatada nao-preferencia alimentar das lagartas para 'Zapalote Chico' e 'BR 201'. Nao-preferencia para oviposicao foi constatada em 'CMS 14C' e 'Zapalote Chico'